Model Comparison

Grok 4 Fast vs Jamba 1.5 Mini

Grok 4 Fast significantly outperforms across most benchmarks. Jamba 1.5 Mini is 1.1x cheaper per token.

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Performance Benchmarks

Comparative analysis across standard metrics

1 benchmarks

Grok 4 Fast outperforms in 1 benchmarks (GPQA), while Jamba 1.5 Mini is better at 0 benchmarks.

Grok 4 Fast significantly outperforms across most benchmarks.

Sun Apr 19 2026 • llm-stats.com

Arena Performance

Human preference votes

Pricing Analysis

Price comparison per million tokens

Jamba 1.5 Mini costs less

For input processing, Grok 4 Fast ($0.20/1M tokens) costs the same as Jamba 1.5 Mini ($0.20/1M tokens).

For output processing, Grok 4 Fast ($0.50/1M tokens) is 1.3x more expensive than Jamba 1.5 Mini ($0.40/1M tokens).

In conclusion, Grok 4 Fast is more expensive than Jamba 1.5 Mini.*

* Using a 3:1 ratio of input to output tokens

Lowest available price from all providers
Sun Apr 19 2026 • llm-stats.com
xAI
Grok 4 Fast
Input tokens$0.20
Output tokens$0.50
Best providerxAI
AI21 Labs
Jamba 1.5 Mini
Input tokens$0.20
Output tokens$0.40
Best providerAWS Bedrock
Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

Grok 4 Fast accepts 2,000,000 input tokens compared to Jamba 1.5 Mini's 256,144 tokens. Jamba 1.5 Mini can generate longer responses up to 256,144 tokens, while Grok 4 Fast is limited to 30,000 tokens.

xAI
Grok 4 Fast
Input2,000,000 tokens
Output30,000 tokens
AI21 Labs
Jamba 1.5 Mini
Input256,144 tokens
Output256,144 tokens
Sun Apr 19 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Grok 4 Fast supports multimodal inputs, whereas Jamba 1.5 Mini does not.

Grok 4 Fast can handle both text and other forms of data like images, making it suitable for multimodal applications.

Grok 4 Fast

Text
Images
Audio
Video

Jamba 1.5 Mini

Text
Images
Audio
Video

License

Usage and distribution terms

Grok 4 Fast is licensed under a proprietary license, while Jamba 1.5 Mini uses Jamba Open Model License.

License differences may affect how you can use these models in commercial or open-source projects.

Grok 4 Fast

Proprietary

Closed source

Jamba 1.5 Mini

Jamba Open Model License

Open weights

Release Timeline

When each model was launched

Grok 4 Fast was released on 2025-08-28, while Jamba 1.5 Mini was released on 2024-08-22.

Grok 4 Fast is 12 months newer than Jamba 1.5 Mini.

Grok 4 Fast

Aug 28, 2025

7 months ago

1.0yr newer
Jamba 1.5 Mini

Aug 22, 2024

1.7 years ago

Knowledge Cutoff

When training data ends

Jamba 1.5 Mini has a documented knowledge cutoff of 2024-03-05, while Grok 4 Fast's cutoff date is not specified.

We can confirm Jamba 1.5 Mini's training data extends to 2024-03-05, but cannot make a direct comparison without Grok 4 Fast's cutoff date.

Grok 4 Fast

—

Jamba 1.5 Mini

Mar 2024

Provider Availability

Grok 4 Fast is available from xAI. Jamba 1.5 Mini is available from Bedrock, Google.

Grok 4 Fast

xai logo
xAI
Input Price:Input: $0.20/1MOutput Price:Output: $0.50/1M

Jamba 1.5 Mini

bedrock logo
AWS Bedrock
Input Price:Input: $0.20/1MOutput Price:Output: $0.40/1M
google logo
Google
Input Price:Input: $0.20/1MOutput Price:Output: $0.40/1M
* Prices shown are per million tokens

Outputs Comparison

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Key Takeaways

xAI
Larger context window (2,000,000 tokens)
Supports multimodal inputs
Higher GPQA score (85.7% vs 32.3%)
AI21 Labs
Less expensive output tokens
Has open weights

Detailed Comparison

AI Model Comparison Table
Feature
xAI
Grok 4 Fast
AI21 Labs
Jamba 1.5 Mini

FAQ

Common questions about Grok 4 Fast vs Jamba 1.5 Mini

Grok 4 Fast significantly outperforms across most benchmarks. Grok 4 Fast is made by xAI and Jamba 1.5 Mini is made by AI21 Labs. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.
Grok 4 Fast scores SimpleQA: 95.0%, HMMT 2025: 93.3%, AIME 2025: 92.0%, GPQA: 85.7%, LiveCodeBench: 80.0%. Jamba 1.5 Mini scores ARC-C: 85.7%, GSM8k: 75.8%, MMLU: 69.7%, TruthfulQA: 54.1%, Arena Hard: 46.1%.
Both models cost $0.20 per million input tokens.
Grok 4 Fast supports 2.0M tokens and Jamba 1.5 Mini supports 256K tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.
Key differences include context window (2.0M vs 256K), multimodal support (yes vs no), licensing (Proprietary vs Jamba Open Model License). See the full comparison above for benchmark-by-benchmark results.
Grok 4 Fast is developed by xAI and Jamba 1.5 Mini is developed by AI21 Labs.